Let me preface this by saying I am the queen of chucking anything and everything in the washing machine, even stuff that says dry clean only, and I've yet to have a disaster. But these are expensive curtains...
They are 100% cotton, lining is a poly cotton mix. If they shrank slightly in length that would be fine as I need to take them up anyway, but I'd rather not loose any width. My mother (who taught me my kamikaze attitude to 'dry clean only') says they may shrink upwards due to the weft(?) but not width ways.
They say dry clean only but would you do it? I know there's lots of alternatives but nothing compares to a good old wash and blow on the line. I'd wash them cool, obvs (30?).